Financial analyst Charles Sizemore predicts that over time, a persistent Microsoft will come to not only thrive but dominate in the mobile computing space, because Apple has no "moats" to prevent customer attrition and its insistence at heavily controlling the ecosystem will drive customers away, while Google's offerings are too "shoddy." It's a bold prediction, but I suppose betting on Microsoft to be persistent and build on its strengths is a safe bet. But will persistence and flexibility be enough?

Google has made with Android for last 4 years.
Sure, WP might be a little more polished NOW, but assuming that actually matters, it will take years for MS to make up for market share it lost to Google.
Those years will be used by Google to make up for whatever shortcomings Android might have in consumers eyes.
Add to that MS currently doesn't have any real exclusive killer feature with WP while being:
- closed
- much less customizable
- much less flexible and OEM friendly (that translates to cost and OEM flexibility itself)
- associated with company known from its predatory practices towards partners (Google could easily blow it too, though).

MS was too attached to its monopoly benefits and throwing money at a problem practices it had in the past. Google managed bypass MS ecosystem while growing as strong financially. Buying more companies just won't cut it this time.

Besides with its current approach MS is aiming directly at Apple, not Android.